Silicon carbide (SiC) is a high-hardness semiconductor material with a greater bandgap than silicon (Si), and is expected to be used extensively in various types of semiconductor devices including power elements, hostile-environment elements, high temperature operating elements, and radio frequency elements. Among other things, the application of SiC to power elements such as switching elements and rectifiers has attracted a lot of attention. This is because a power element that uses SiC can significantly reduce the power loss compared to a Si power element. In addition, by utilizing such properties, SiC power elements can form a semiconductor device that has an even higher breakdown voltage, would involve smaller loss, and has a smaller size than Si power elements (see Patent Document No. 1, for example).
It is important for a semiconductor device that uses silicon carbide to determine what terminal structure is used to ensure a breakdown voltage in OFF state. In general, a terminal structure is arranged on the outer periphery of a chip on which a semiconductor element is provided. As the terminal structure, a field limited ring (which will be referred to herein as “FLR”) structure, a junction termination extension (which will be referred to herein as “JTE”) structure, a mesa structure or any other suitable structure is used extensively. The FLR and JTE structures have a dopant ion implanted region on the outer peripheral area of the chip. On the other hand, the mesa structure is formed by a level difference which has been created on the outer peripheral area of the chip. In the mesa structure, a dopant ion implanted region is sometimes provided in the vicinity of the level difference, too.